Centrifugal bowl



Feb. 20, 1945. A. E. FLOWERS CENTRIFUGAL `BOWL Filed Aug'. 5, 1942 W. w N 6 n L www N 0 f A FZ 5@ 7. w /l A,

A W/ /VESS @gaffe/a Patented Feb. 20, 1945 UNITEDV'f-STAT 'PATENT v 0111516151 v a *QENTRIFUGAL BOWL a l Alan E. FIoWeraPoughkeepsie, 4N.`Y.', assigner to The De Laval Separator Company,l New York,v N. Y., a corporation of New Jersey' Application Augst 5, 1942, seriallNo'. 453,611

The object, of my invention is to providea centrifugal bowl thatv is especially adaptedvto the preparation of bloodplasmafor use as a substitute for direct transfusion of whole blood. The primary requisite for lwhole blood trans'- fusion is that the blood of the donor shall bev of the. same type `as that of the'patient. It, has been found that the characteristics'gof a. donors blood that prohibit itsv use with a patient whose blood is- ,ofy a different typ'e Vexist in thetbl'ood vcorpuscles, principally red cells, and that, if the removal of these is complete the 'plasma can be ,used Y regardless of the type of blood from which `it is prepared. It yhas beenfound thaty such plasma can even be dried, preserved asa powder and, when needed, dissolved in Watena-nd injectedy 4 Claims; (c1. 233,449)

for cleaning and inspection. Specifically, I have found thislslight leakage to occur between the central `feed tube andthe distributor and between the upper side of the lower part of the distributor'and the underside ofthe bottom disc.

v In' other words, the perfectly separated lighter into the veins of a'person'sufering from shock or loss of blood. i Y

These facts are well understood. It is also known that the separation of the plasma from' the red blood corpusclesY can be eiected in a centrifugal separator; A most eilicient type of separator is one which comprises a bowl provided with discs, a distributor which the bowl surrounds, and a feed tube or central receiving chamber extending Within the distributor and communicating, through the distributor, with the bowl beneath the liner of discs therein', It is necessary, in bowls `of thistype, in order that vally surfaces can be cleaned and sterilized to the Yhigh degree needed in surgical work, that the fbowl should be separable to suchk an extent ythatv all .surfaces that come in contact with the material being treated are accessible for washing, brushing and inspection. Such bowls are known, but theirl use in the separation of plasma'from red blood corpuscles *has not been satisfactory.

There is always a very slight, but appreciable,

tamination, when the centrifuge is'used for mostk purposes, 'isso small as to be practically negligible, but s uch slight degree of contamination isv inadmissible in.. ,the-,separationy of blood plasma,

As* above stated, the jfailure of separatorsofk the type described to giveperfect separation y'has been attributed to an inherent incapacity of any 'centrifuge' to effect'a reallyclean separation.

I have found,"however, lthat, this assumption isnot warrantedl so far as concernsthose members lofl the bowl which, in. operation,. effect the constituent is contaminated before it escapes,`

from the bowl, with the incoming liquid to be separated. n

wIn the accompanying drawing, Fig. `1 of which isf'a vertical section through a separator of the typeI have described and Fig. 2 a cross-section on the line 2-7-2 yof Fig. 1, I have illustrated means thatv effectively seals the4 joints between these parts, wherebyall leakage is prevented. In a separator so constructed, the plasma is separated wholly free` of red blood -corpuscles The `.struc-4 tural details of the illustrated centrifuge will be described and the novel elements thereof particu-y larly indicated.` y ,a a

A spindle I supports and drives the centrifugal bowl; i The bowl comprises a combination bottom` 2V and central tube orreceiving chamber 3f;

ashell. lhavinga neck ZII;` distributor 5; a plu-' l rality of frustro conical members, technically called discs, including a bottom disc 6, a top disc I with neck` 8, and a plurality of intermediate discs 9 (only two of which are shown)4 'I yth'ewall of the central tube or receiving chamber 3 communicates, through a passage lllalong the inside ofthe distributor 5, with an annular chamber I5, vfrom whichfa numberof` outlets I6 lead to an equal number of passages I'I between ,the bottom discr w6 and the, bowl bottom 2.

Throughthe Vbottoni disc, near 'to its periphery,l

distributing holes I8 lead tosimilar holes I9 in I the intermediate discs 9.

the neck of the bowl shell. 28 is the customaryr rubber bowl ring that seals the joint between the bowl bottom and the shell.

29 is a resilient compressible ring which seals the space and prevents leaks between the central tube 3 and the distributor 5. 30 is a similar ring that prevents leaks between the larger diameter portion of the distributor y5 and the under side of the bottom disc 6.

In operation, blood fed into the tube II is discharged from the outlet I2 to the inside of the tube 3, whence it flows through the opening I3 and passage I4 to the annular chamber I5 which it lls. From this chamber the blood flows through the outlets I6 and passages I 'I to the distributing holes I8 and I9, which feed the blood to all the spaces between the discs 9. In these spaces the plasma, which is the lighter constituent, is forced to flow toward the center and then up through the passages 2I and is discharged from the outlets 22 into a receptacle, not shown. The blood corpuscles, which are heavier than the plasma, separate from the plasma while between the discs and move outward to the space between the discs and bowl shell then upward and inward through passages 26 to the openings 2'I through which they escape into a receptacle not shown.

`I have found that interposing resilient compressible rings between the parts hereinbefore specified will stop all leaks of unseparated blood into the purified plasma and cause perfect work by a bowl that bowl otherwise give results far short of those required to effect aclean separation of the plasma.

While the improved centrifugal bowl is particularly adapted to and intended for the particular use hereinbefore described, it will be found useful, and often highly desirable, in other fields, for example:` the separation of colloidal contaminants from liquids in whichthey are dispersed, such as airplane and Diesel engine lubricating oils, medical preparations, pure chemicals, etc. Obviously, my improved centrifugal bowl, with compressible seals between separable parts, is adapted for general use, since the cleaner separation that it effects is desirable even when not absolutely required.

What I claim and desire to protect by Letters Patent is:

lf In a centrifuge for separating blood plasma suitable for transfusion from other constituents oi' whole blood, the combination of a central tube enclosing a whole blood receiving chamber; a bowl chamber; said bowl chamber comprising a bowl bottom, a bowl shell having an upper neck provided with an outlet for separated plasma and a tubular member whose upper part fits around the receiving chamber and whose lower part communicates with the receiving chamber and forms a 'distributor` and a pile of discs within the bowl chamber the lowermost of which rests on the lowerl part of tliedistributor` and is spaced from the bowl bottom and provides communication between the distributor and the bowl chamber, and means preventing contamination of the outwardly flowing lighter separated constituent with inowing liquid to be separated, said means comprising a seal between the contacting walls of the receiving chamber and distributor and a seal between the contacting walls of the distributor and the bottom disc.

2. In a centrifuge for separating blood plasma suitable for transfusion from other constituents of whole blood, the combination of a central tube enclosing a whole blood receiving chamber; a bowl chamber; said bowl chamber comprising a bowl bottom, a bowl shell having an upper neck provided with an outlet for separated plasma and a tubular member whose upper part fits around the receiving 'chamber and whose lower part communicates with the receiving chamber and forms a distributor, and a pile of discs within the bowl chamber the lowerrnost of which extends from the lower part of the distributor and is spaced from the bowl bottom and provides communication between the distributor and the bowl chamber, and means insuring against leakage of the inowing whole blood into separated blood plasma and thus preventing contamination of the latter, said means comprising, a seal, between the contacting walls of the receiving chamber and the tubular distributor, located above the outlet from the receiving chamber to the distributor and preventing flow of whole blood from the receiving chamber except into the distributor, and va tight connection between the lower partof the distributor and the bottom disc preventing ilow of whole blood from the distributor except into the bowl chamber.

3. In a centrifuge primarily intended for separating blood plasma suitable for transfusion from other constituents of whole blood, `the combination of a bowl comprising a bottom and a shell having a neck, a central receiving chamber extending into the bowl neck, a top disc in the bowl also extending into the bowl neck and :A spaced from the central receiving chamber to provide an outlet passage for the lighter separated constituent, a removable distributor surrounding, and throughout a substantial part of its height iitting, and communicating with an opening in, the central receiving chamber and forming the inner wall of the bowlvand terminating at its top below the discharge from said outlet passage, a bottom disc in, and spaced from the bottom bf, the bowl and throughout a substantial part of its area removably tting against the distributor and the space below which provides communication between the distributor and the separating space enclosed by the bowl, and means preventing contamination of the outward- 1y flowing lighter separated constituent with inilowing liquid to be separated, said means comprising a seal between the walls of the receiving chamber and distributor 'where they contact above the outlet from the receiving chamber and another seal between the contacting walls of the distributor and the bottom disc; f

4. In a centrifuge primarily intended for sep arating blood plasmav suitable for transfusion from otherconstituentsof whole blood, the combination with ay centrifugal bowl having a central tubular element providing a central receiving chamber, a distributor comprisingv avtubular element which surrounds and is concentric with the receiving chamber and has .a close t thereon but is slidable thereon to facilitate removal for cleaning, there being a feed opening in 'the receiving chamber wall and, communicating therewith, a channel in the lower part of the distributor, a liner in the bowl chamber comprising a pile of dises, the lower end of the distributor being outwardly enlarged and resting upon the bowl bottom and having an upper sloping face adapted to support the bottom disc 'in such position as to space it from the bowl bottom and thus provide a passage affording communicationbetween the distributor channel and the separating space of the bowl, the separating chamber having an outlet for the lighter separated constituent outside the upper end of the yreceiving chamber and above the upper end of the distributor charnber, and resilient compressible rings, one between the central receiving chamber and the distributor between the upper and lower ends oi their 'contacting walls, and the other between the bottom disc and the disc-supporting face of the enlarged lower end :of the distributor, thereby preventing contamination of the separated outflowing lighter liquid constituent with inow ing liquid to be separated.

ALAN E. FLOWERS. 

